The present invention relates to vacuum cleaners. Such vacuum cleaners are well known for collecting dust and dirt, although wet-and-dry variants which can collect spilled liquids as well are also known. Typically, they are intended for use in a domestic environment, although they also find uses in other environments, such as worksites. Generally, vacuum cleaners are electrically powered and comprise an electric motor, an electrical on-off switch for a user to operate said motor, a fan connected to an output shaft of said motor, an inlet for dirty air, an outlet for clean air and a collection chamber for dust, dirt and possibly also liquids. Electrical power for the motor may be provided by a source of mains electricity, in which case the vacuum cleaner will further comprise an electrical power cable, by a removable and replaceable battery pack, or by one or more in-built rechargeable cells, in which case the vacuum cleaner will further comprise some means, such as a jack plug, for connecting the vacuum cleaner to a recharging unit. When the vacuum cleaner is provided with electrical power from one of these sources and the on-off switch is set to the “on” position, the electric motor drives the fan to draw dirty air along an airflow pathway in through the dirty air inlet, via the collection chamber to the clean air outlet. Interposed at some point along the airflow pathway, there is also provided some means for separating out dust and dirt (and possibly also liquids) entrained with the dirty air and depositing these in the collection chamber. This separation means may comprise one or more filters and/or a cyclonic separation device. An example of such a hand-holdable vacuum cleaner in which the separation means comprises a filter is disclosed in European patent application no. EP 1 523 916 in the name of the present applicant.